You need to assess the speed and distance of any vehicles on the major road.
You may use the ‘Walk Across, Drive Across’ rule to decide if you are going to wait or emerge.
Emerging Left
Look at the vehicle approaching from your right. You need to drive out, and speed up in front of it, without causing it to Stop, Slow or Swerve. Ask yourself, “would I walk all the way across the road and all the way back in front of the car (this is from the left kerb to the right kerb, and then back to the left kerb)?” If the answer is “Yes”, then you probably have time to drive out in front of it.
Emerging Right
Look at the vehicle approaching from your right. You need to cut in front of it, without causing it to Stop, Slow or Swerve. Ask yourself, “would I walk across the road in front of it (this is from the left kerb to the right kerb?
If the answer is “Yes”, then you probably have time to drive out in front of it.
At the same time, you need to look at the vehicle approaching from your left.
You will have to drive out, and speed up in front of it. Ask yourself, “would I walk all the way across the road and all the way back in front of the car (this is from the left kerb to the right kerb, and then back to the left kerb)?” If the answer is “Yes”, then you probably have time to drive out in front of it.
If the answer is no then wait until you find a safe gap.